Ascended Fanon: Scott Fischer wasn't given a superhero name during his time in the book, but prominent letter writer Charles J. Sperling decided that his name had to be "Blaze". Near the end of that era, the book's editor said that "Scott has adopted the name of Blaze, I think, but he hasn't officially used it."
Promoted Fanboy: The series has been out of the mainstream enough that many of the writers were fans of earlier series. Paul Kupperberg, Grant Morrison and John Byrne were all fans of the original Drake run, Rachel Pollack had written letters to the book during Morrison's tenure, and Keith Giffen admitted he'd been trying to launch a Doom Patrol book for years.
Joe Casey's Automatic Kafka started life as a Doom Patrol pitch.
Another rejected pitch that has come to light in the past few years was one by Scott Lobdell and Ilias Kyriazis, about an all-new Doom Patrol featuring stalwarts Cliff Steele and Gar Logan leading Tefé Holland, Platinum, Madame .44, Zatara and Bizarro, of all people. Kyriazis' blog also features concept art of Changeling, Tefé and Platinum combining into a platinum sword-wielding, tree-limbed green shark.